A) 6 min.to empty | B) 6 min.to fill |

C) 9 min.to empty | D) 9 min.to fill |

Explanation:

Clearly,pipe B is faster than pipe A and so,the tank will be emptied.

part to be emptied = 2/5

part emptied by (A+B) in 1 minute=$\left(\frac{1}{6}-\frac{1}{10}\right)=\frac{1}{15}$

$\frac{1}{15}:\frac{2}{5}::1:x$

$\frac{2}{5}*15=6mins$

so, the tank will be emptied in 6 min

A) 70 lit | B) 170 lit |

C) 90 lit | D) 190 lit |

Explanation:

Given A alone can fill the tank of capacity 240 lit in 16 hrs.

=> A can fill in 1 hr = 240/16 = 15 lit

=> B alone can fill the tank of capacity 240 lit in 12 hrs.

=> B can fill in 1 hr = 240/12 = 20 lit

Now, (A + B) in 1 hr = 15 + 20 = 35 lit

But they are opened for 2 hrs

=> 2 x 35 = 70 lit rae filled

Remaining water to be filled in tank of 240 lit = 240 - 70 = 170 lit.

A) 200 hrs | B) 240 hrs |

C) 300 hrs | D) 270 hrs |

Explanation:

Volume of water collected in the tank in 1 hour

⇒ (0.3 × 0.2 × 20km × 1000mts) = 1200 m cubic

If after t hours, the water is at height of 12m,

1200t=200×150×12

⇒ t = 300 Hours.

A) 32.5 hrs | B) 29.25 hrs |

C) 30.30 hrs | D) 31 hrs |

Explanation:

Let the leak will empty the tank in x hrs

Then, 1/9 - 1/x = 1/13

x = 29.25 hrs

A) 4 hrs 15 min | B) 3 hrs 24 min |

C) 4 hrs 51 min | D) 3 hrs 45 min |

Explanation:

Time taken by one tap to fill half of the tank = 3 hrs.

Part filled by the taps in 1 hour = 4 x 1/6 = 2/3

Remaining part = 1 - 1/2 = 1/2

2/3 : 1/2 :: 1 : p

p = 1/2 x 1 x 3/2 = 3/4 hrs. i.e., 45 min

So, total time taken = 3 hrs 45 min.

A) 31 min | B) 29 min |

C) 28 min | D) 30 min |

Explanation:

Part filled by (A + B) in 1 minute = (1/60 + 1/40) = 1/24

Suppose the tank is filled in x minutes.

Then, x/2(1/24 + 1/40) = 1

(x/2) * (1/15) = 1 => x = 30 min.

A) 32 hrs | B) 24 hrs |

C) 28 hrs | D) 26 hrs |

Explanation:

1/K + 1/L + 1/M = 1/8 (Given)

Also given that K = 2L and L = 2M

=> 1/2L + 1/L + 2/L = 1/8

=> (1 + 2 + 4)/2L = 1/8

=> 2L/7 = 8

=> L = 28 hours.

A) 15 min 20 sec. | B) 16 min 40 sec. |

C) 13 min 10 sec. | D) 14 min 40 sec. |

Explanation:

Part filled in 4 minutes = 4(1/15 + 1/20) = 7/15

Remaining part = 1 - 7/15 = 8/15

Part filled by B in 1 minute = 1/20

1/20 : 8/15 :: 1 : k

k = (8/15 )x 1 x 20 = 10( 2/3) min = 10 min 40 sec.

The tank will be full in (4 min. + 10 min. 40 sec) = 14 min 40 sec.